User blog:Samuli.seppanen/Various failed experiments
During my work on the cheiroballistra I've ran into a bunch of manufacturing techniques and technical solutions that seemed reasonable at the time, but proved to not work properly in the end. This blog post outlines some of them, and why they failed. At one point I thought about making the tenons of the little ladder beams from a separate pieces of steel: There is no particular reason why this would not work. It just turned out that when the little ladder is made from thick enough (~6mm) steel there's no reason not to just forge the tenons from the beams themselves. It the beams were made from thinner steel then separate tenons would make more sense. I've also tested various ways to make the field frame rings. Two such experiments, which failed, are shown in the pictures below: On the left a hole has been punched through a steel plate. This was done by placing a strong steel pipe on top of the anvil, the heated plate on top of it, and by hammering the steel plate against the pipe. While this worked, there were a couple of issues: * Lots of force was required, as heating the steel to light yellow was tricky with the forge setup I had then. * Due to combination of heat and the relatively thin wall of the pipe (~4mm) the pipe actually collapsed quite a bit under continuous beating. * The hole is not as uniform as I had hoped: it would have required lots of finishing with a file. Even if punching the hole had went perfectly, lots of cutting, grinding and filing would have been required to make the plate look like a field frame ring. The attempt on the left was more traditional, but the steel was flattened too early, before bending it properly around the horizontal ring forging template. This caused the ring to become too narrow, as lots of hammering was needed to bend it to a ring. I had encountered the same problem earlier when attempting to make rings from flat steel instead of round stock. The next failure is in retrospect pretty annoying. In order to save a bit of weight I decided that 5mm thick field frame rings should be adequate, as they were not under lots of stress. This turned out not to be entirely true, and under 320hz torsion springs the rings bent visibly: So I had to redo the entire field frames - not a small task - and use 8mm rings instead. Here's a picture of a new field frame when it was being assembled: The last experiment in this blog post is the little arch forging form. The idea was that the core of the little arch would be forged from a single piece of steel to which the forks would be attached: The idea was and is still reasonable. The problem was that heating a long piece of steel in the forge setup I used was very difficult. Attaching the form to the anvil using clamps did not work that well, either - it was simply not rigid enough. So in the end I ended up making the curve from a separate piece of stronger steel welded to two straight beams. The forks were then welded to these straight beams. Category:Blog posts Category:Backup Category:Little arch Category:Field frame Category:Metalworking